Hydrogen Electrolyzer & Fuel Cell Manufacturing worked example

Hydrogen Purge Loss with hydrogen purge flow rate of 2.5 Nm³ / hr: a worked example

Suppose hydrogen purge flow rate falls to 2.5 Nm³ / hr. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate hydrogen lost during stack purging and conditioning at end-of-line test from purge flow rate in Nm3 per hr, total purge runtime, and the delivered cost per Nm3 of hydrogen.

The inputs for this scenario

  • Hydrogen purge flow rate: 2.5 Nm³ / hr (the input this scenario stresses; the baseline uses 5)
  • Total hydrogen purge runtime per stack: 1.5 hr (held at the documented default)
  • Delivered hydrogen cost: 7.5 $ / Nm³ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Hydrogen purge consumption per stack = purge flow rate × total purge runtime.
  • Hydrogen purge cost per stack works out to 28.13 $ at these inputs, and this is the headline figure for the scenario.
  • Hydrogen purge consumption per stack works out to 3.75 units at these inputs.
  • Total hydrogen purge runtime works out to 1.5 hr at these inputs.
  • Delivered hydrogen cost works out to 7.5 $ / unit at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where hydrogen purge flow rate sits at 5 Nm³ / hr and the headline result is 56.25 $, this scenario comes in 50% below the baseline at 28.13 $.
  • It multiplies hydrogen purge flow rate by total purge runtime to get consumption per stack, then multiplies by delivered hydrogen cost to get purge cost per stack. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Hydrogen purge cost per stack: 28.13 $ (headline result)
  • Hydrogen purge consumption per stack: 3.75 units
  • Total hydrogen purge runtime: 1.5 hr
  • Delivered hydrogen cost: 7.5 $ / unit

Run it with your numbers

  • To rerun this with your own numbers, open the live Hydrogen Purge Loss calculator, set hydrogen purge flow rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.